Revision total ankle replacement: an early look at agility to INBONE

INTRODUCTION. The role of total ankle replacement (TAR) is expanding in the United States. As the number of ankles implanted increases, undoubtedly the number of failures will increase. Several reports in the literature have dealt with salvage of the failed TAR through various methods. MeTHODS. A retrospective chart and radiographic review was performed on all patients who had conversion from a failed Agility TAR to an INBONE TAR at 2 centers and had been performed at least 12 months prior to the study. Exclusion criteria included any patient converted from a different type of TAR, primary TAR, patients followed less than 12 months, and surgical approach other than the standard anterior incision. RESULTS. Five patients met inclusion criteria. The average age was 65.6 ± 13.6 years (range = 45-79 years). Complicating comorbidities were found with 4 patients. The average follow-up was 17.2 ± 6.6 months (range = 7-25 months). The cause of failure of the original Agility TAR was coronal plane deformity in 3 patients, and 1 patient each failed from extensive heterotopic ossification or infection. All patients presented with pain. In 4 cases, there was component subsidence at the talus, tibia, or both. All patients had adjunctive procedures at the time of the revision, including malleolar screw placement in 4 patients and hindfoot arthrodesis in 2 patients. All patients had either 4 or 5 tibial stem components placed. During the follow-up period, 3 patients required additional surgery, including 2 patients classified as failures (1 transtibial amputation and 1 tibiotalocalcaneal arthrodesis). DISCUSSION. This salvage option is technically demanding. The authors caution against TAR revision by conversion in the place of previous infection and in ankle imbalance not amenable to reconstruction. In all cases the initial deformity was corrected. The early results, however, demonstrate high risk of early failure and positional changes.